2,585 research outputs found

    Second law analysis of a natural gas-fired steam boiler and cogeneration plant

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    A second law thermodynamic analysis of a natural gas-fired steam boiler and cogeneration plant at Rice University was conducted. The analysis included many components of the plant including piping, valves, boilers, turbines, piping specialties and various other pieces of equipment. Typical steady state plant operating conditions were determined based on available trending data and the resulting conditions are representative of the bulk of the plants operating hours. The exergy destruction from individual components in the plant was calculated based on these operating conditions to determine the true system losses. The largest source of exergy destruction within the plant was found to be the gas turbine system under typical operating conditions. Recommendations for efficiency improvement based on the analysis are discussed. The addition of a back pressure steam turbine to the system is shown to improve the overall system efficiency from 21% to 22.4% while increasing the plant power generation capacity by 9.8%. A reduction in the plant steam header pressure in conjunction with the addition of the steam turbine improved the overall system efficiency to 23%, while increasing plant power generation by 12%. In addition, a first law thermodynamic analysis was performed and first and second law efficiencies are compared for several components.\u2

    The outsider within the Victorian comnmunity: Nicholas Bulstrode in Middlemarch and Michael Henchard in the Mayor of Casterbridge

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    Many have written about the theme of interconnection in George Eliots Middlemarch, where individual lives and fates are woven into the larger life of the community, but few have written about this theme in relation to The Mayor of Casterbridge, Thomas Hardys fictional and historical depiction of Dorchester and the larger area of Wessex. Hardys novel about the life and death of a man of character, is a complex and psychological characterization, but it also is representative of a particular province during a time of rapid change in community structure, just as Middlemarch is. I would like to suggest that it is through the complex characterizations of the outsider and outcast from the community that Eliot and Hardy reinforce the theme of interconnection. My aim will be to highlight this point through an examination of Nicholas Bulstrode, the Middlemarch banker with a shady past, and Michael Henchard, the Casterbridge mayor with skeletons of his own, illustrating the integral role these two characters play in reinforcing the authors themes of interconnection and disconnection within their novels. Although Henchard is the main character of Casterbridge and Bulstrode a minor character in Middlemarch, both characters are integral to the notion of the outsider within the enclosed Victorian community. I will develop this idea by first looking at the role community plays in each characters concept of self. Then I will look at the degree to which these characters are a part of their communities and the point at which this connection begins to unravel. Finally, I will examine the role introspection plays in revealing to each man his lack of connection, not only to his community, but also to himself, thus illustrating the Victorian concept of interconnection and interdependence as a vital part of selfhood and perhaps of survival

    Genomic stability in response to high versus low linear energy transfer radiation in Arabidopsis thaliana.

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    Low linear energy transfer (LET) gamma rays and high LET HZE (high atomic weight, high energy) particles act as powerful mutagens in both plants and animals. DNA damage generated by HZE particles is more densely clustered than that generated by gamma rays. To understand the genetic requirements for resistance to high versus low LET radiation, a series of Arabidopsis thaliana mutants were exposed to either 1GeV Fe nuclei or gamma radiation. A comparison of effects on the germination and subsequent growth of seedlings led us to conclude that the relative biological effectiveness (RBE) of the two types of radiation (HZE versus gamma) are roughly 3:1. Similarly, in wild-type lines, loss of somatic heterozygosity was induced at an RBE of about a 2:1 (HZE versus gamma). Checkpoint and repair defects, as expected, enhanced sensitivity to both agents. The "replication fork" checkpoint, governed by ATR, played a slightly more important role in resistance to HZE-induced mutagenesis than in resistance to gamma induced mutagenesis

    High atomic weight, high-energy radiation (HZE) induces transcriptional responses shared with conventional stresses in addition to a core "DSB" response specific to clastogenic treatments.

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    Plants exhibit a robust transcriptional response to gamma radiation which includes the induction of transcripts required for homologous recombination and the suppression of transcripts that promote cell cycle progression. Various DNA damaging agents induce different spectra of DNA damage as well as "collateral" damage to other cellular components and therefore are not expected to provoke identical responses by the cell. Here we study the effects of two different types of ionizing radiation (IR) treatment, HZE (1 GeV Fe(26+) high mass, high charge, and high energy relativistic particles) and gamma photons, on the transcriptome of Arabidopsis thaliana seedlings. Both types of IR induce small clusters of radicals that can result in the formation of double strand breaks (DSBs), but HZE also produces linear arrays of extremely clustered damage. We performed these experiments across a range of time points (1.5-24 h after irradiation) in both wild-type plants and in mutants defective in the DSB-sensing protein kinase ATM. The two types of IR exhibit a shared double strand break-repair-related damage response, although they differ slightly in the timing, degree, and ATM-dependence of the response. The ATM-dependent, DNA metabolism-related transcripts of the "DSB response" were also induced by other DNA damaging agents, but were not induced by conventional stresses. Both Gamma and HZE irradiation induced, at 24 h post-irradiation, ATM-dependent transcripts associated with a variety of conventional stresses; these were overrepresented for pathogen response, rather than DNA metabolism. In contrast, only HZE-irradiated plants, at 1.5 h after irradiation, exhibited an additional and very extensive transcriptional response, shared with plants experiencing "extended night." This response was not apparent in gamma-irradiated plants

    Generating structured music for bagana using quality metrics based on Markov models.

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    This research is partially supported by the project Lrn2Cre8 which acknowledges the financial support of the Future and Emerging Technologies (FET) programme within the Seventh Framework Programme for Research of the European Commission, under FET Grant No. 610859
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